This prospective, observational study addresses the overarching hypothesis that brain dysfunction and structural injury are present at one month post- sports concussion (SC) in asymptomatic high school athletes who have been cleared by a licensed health provider (LHP) for return to play (RTP). We hypothesize that a biomarker measured from serum on the day of recruitment is prognostic of recovery by one month post-SC. High school athletes will be recruited within three days post-SC (n=24) from consecutive referrals to Memorial Hermann Sports Medicine Clinic in Houston. A comparison group of 24 high school athletes with orthopedic injury (OI) will also be recruited. Weekly assessment via telephone of post-concussion symptoms will identify athletes who are asymptomatic by one month and cleared for RTP. At one month post-injury both groups will return to clinic for neurobehavioral assessment, magnetic resonance imaging (MRI), diffusion tensor imaging (DTI) and resting state functional magnetic resonance imaging to measure functional connectivity (FC) of brain regions. Data analysis will test between-group differences in integrity of white matter tracts (DTI) and FC of brain regions. Biomarker levels will be analyzed in relation to brain imaging and neurobehavioral recovery at one month in SC group.